Motor fuel



D. W. HOGE March 2l, 1.933.

MOTOR FUEL 19, 1928 2 Sheets-Sheet l Original Filed Dec March 2l, 1933.v

Original Filed Dec. 19, 1928 D. w. HOGE MOTOR FUEL 2 Sheets-Sheet' 2 I Continuation of application Serial No.

Patented Mar. 21, 1933 UNITED STATES PATENT OFFICE DANIEL W. HOGE, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO CARLOS W. N EWBERY, OF LOS ANGELES, CALIFORNIA MOTOR FUEL This invention has reference to fuels for internal combustion engines and more particularly to a motor fuel derived from constituents of crude turpentine, this material in addition to being highly superior as va fuel, having properties Which render it capable of suppressing detonation When used alone as a motor fuel or when mixed with gasoline.

It is a purpose of the invention to produce by the destructive distillation or cracking of crude turpentine, which, disregarding impurities, is essentially a solution of rosin in oil of turpentine, or by the cracking of either of these constituents, preferably the rosin, a product or series of compounds of aromatic nature differing characteristically in specific gravity and boiling range, and of which a certain range is particularly suited for use as motor fuel. Typical processes bvwhich -the present product mav be obtained are described in my copending application, of which the present application is a continuation. entitled Method for treating resins, Serial No. 327.013, filed December 19, 1928. In speaking of crude turpentine hereinafter it will be understood that I refer to the resinous' exudate as obtained in the crude state from species of pine and comprising rosin andoil of turpentine, or to refined crude turpentine from which impurities such as foreign solids and Waterhave been removed.

Oil ofvturpentine, obtained commercially by the steam distillation of crude turpentine from which the comparatively non-volatile rosin remains asa residue. and also wood turpentine obtained by distillation from dead wood, and which may also be treated to obtain the present product, consist mainly of the hydrocyclic pinenes, and have close boiling ranges from about 310 to 350 F. The residual solid rosin -or colophony remaining after distillation of oil of turpentine from the crude turpentine, consists mainly of abietic acid having a melting point around 300 F., and cannot be distilled at normal `pressure without undergoing extensive decomposition, the distillate instead of solidifying, .being in the form of an oily liquid lmovvn commercially as rosin oil. The latter has a comparatively broad boiling range, say from compounds of aromatic nature or compounds 327,013, filed `December 19, 1928. This application led J'uly 20, 1929. Serial No.v 379,810.

100 to 700o F., and comprises a complex mixture of compounds, some of which are of the aromatic series, in addition toa considerable amount of organic acids. The bulk of the constituents of rosin oil however cannot-be considered aromatic in nature due to insolubility of a considerable percentage of the oil in concentrated sulphuric acid, and in which aromatic compounds characteristically are soluble. Thus it may be noted at this point that by the mere heating and vaporizing of rosin, although in this operation cracking occurs to a certain degree, the cracking reaction does not take place to such an extent as to substantially convert the distillate into possessing the properties of aromatics. In order to obtain products of the nature comprising the invention, turpentine or rosin is subjected to cracking to such an extent as 7o to convert the distillate almost entirely into aromatic or kindred compounds, this being indicated by the factthat a typical distillate is found to dissolve at normal temperatures to the extent of -94c% or more in concentrated 75. sulphuric acid. Also the products are comparatively reeof organic acids, this probably being due to the temperature of the cracking operation being suciently high to break down the carboxyl groups characteris- V tic of the acidic compounds. As will be later noted, a comparison of the specific gravities and boiling points of the products gives further evidence of their being aromatlc in nature. ,f 85 AThe' product embodied in the invention may be obtained as Will later be described, from 'the above mentioned constituents of crude turpentine, preferably the rosin, 'and has such characteristics as to render it high- 1y superior for use as motor fuel. Although the product flnds its present and most general use as a non-detonating motor fuel and addition to the useof the present product by itself as motor fuel, the invention broadly contemplates the admixing of thepresent product with common motor fuels to render 5 them non-detonating.

Typically and preferably, the present motor fuel is given a distillation range of yor within say 100 to 450 F., roughly correspon ding to the boiling range limits of the various grades of commercial gasoline. It will be understood of course that the boiling range of the fuel made under -certain conditions vary somewhat beyond these limits, or it paratively closer boiling range within these limlts under other conditions, the temperatures given therefore representing the usual and t pical maximum boiling range characteristic of the usual motor fuels. As a-result of a series of tests made on the fuel. it is found to have a heating value around 21,400 B. T. U. per pounds,ap roximately 1000 B. T. U.s'higher than or inary gasoline, these tests further indicating that subu stantially increased mileage may be had over that obtainable with gasoline, by the use of this fuel. This feature is of great importance with reference to the use of the fuel in airplanes, since it is essential that the maximum 3 .mileage be obtained from a given quantity of fuel, especially in cases where the duration of the Hight may be determined by the amount of fuel that can be carried. Tests made on-the product in motors speciall equipped -for determining the anti-knoc character of fuel indicate that although motors may be operated under extremely severe condltions and under heavy loads, detonation is substantially entirely suppressed. Similar tests have shown the product to have non-detonating properties to a high degree that cannot be given to gasoline even by its treatment with known anti-knock compounds such as tetra-ethyl-lead.. 'It is understood that increasing amounts of for instance tetraethyl-lead, when added to gasoline, serve to increase its non-detonating properties up to certain degree, but that beyond that point the tetra-ethyllead appears to have little effect 1n suppressing further detonation. Thus in the operation of some types of motors un'der extremely severe conditions, it has heretofore been impossible to prevent knocking by the use of gasoline vrendered non-detonating to 5 the highest 4pessime degree by the use ef eer- .tain common anti-.knock reagents.4

It 1s found that the present fuel is substan- `tlally the equivalent of benzol in its nondetonating properties, andas is well known,

benzol is among the most effective of known materials vfor suppressing detonation. Approximately 16% of volume of the product mixed with gasoline is the equivalent of about j l'1.8 cc. of ethyl fluid per gallon of gasoline 5 this being about the usual amount of the lead may be desired to give to the product a comcompound used, although as previously mentioned, by increasing the proportion of the present material, the anti-knock properties of the fuel mixture will be increased accordingly, whereas a limit is reached at a comparatively lesser degree by increasing the amounts of the other. By the use of benzol as a non-detonating compound results similar to those obtained by the addition of the present productwould be obtained, the highcost of benzol, however, 'preventing its use for this purpose whereas the present material may be produced at a comparatively low cost.

obtaining the product, turpentine or rosin is subjected to vaporization and the vapors heated to a cracking temperature preferably between 600 and 1200'l F., the crackedva-V pors then being fractionated by any well known means to give a product having the de- In carrying vout the preferred method of f sired volatility range and physical characx teristics. 'A typical apparatus for carrying out this method of production as well as the 'nature of the properties of the product com- Due to the availability of large quantities of rosin at comparatively low cost and which are obtained in the nature of a by-product in the extraction of oil of turpentine from the crude -turpentine, the production of the fuel from rosin appears to have the greatest economic possibilities. And therefore during the following discussion, the product will be described mainly with reference to its production from rosin. It will be understood that I refer here to all rosinsjof this nature regardless of the method employed in their production and their sources, ,for .n

example whether they be obtained fromV the exudate from living confierae, or by distillation from dead trees and stumrps. Y

Referring i'rst to Fig. 1, the evaporator or" still 10 is charged with rosin in solid form and fired to a temperature s uiicient to vaporize the charge, the vapors (vaporized rosin oil) being conducted through line 11 to the tubular superheater which preferablyis of thetype described'inmy copending application No. 291,712 -filed July 11, 1928. Upon flowing through the superheater, the

vapors are heated to a temperature between 600 and 1200 F., and preferably around 900' F., at which temperature the vapors are thermally decomposed or cracked to form compounds characterized in one respect by their higher boiling point, as will later be noted. The cracked vapors from the superheater are conducted through line 13 to the fractionating tower 14. a suitable trap 15 being placed in the vapor line to remove any liquid or carbonaceous bodies that may be carried in the vapor stream, and the materials in the trap being returned to the still 10 through line 16. The fractionating tower 14 is typical of any suitable means for obtaining from the cracked vapors a product having the desired predetermined boiling range. The cracked vapors from the superheater pass upwardly through the fractionating tower 14, a. portion of the outlet vapor in line 17 being condensed in the condenser 18 and returned to the tower as reflux, and the liquid product being drawn oft from the tower through line 19, at a predetermined point according to the volatility range which it is desired to give to the product. Thus in the present instance,

the product fraction removed from the fractionating tower 14 through line 19 has a vola= tility range of substantially 100 to 450 F.

The higher boiling point fractions are removed at the base of the tower through .line 20, the final extremely volatile vapors or fixed gases being condensed in the condenser 211 In a typical run. the total yield of distillate from the rosin charge in the still 11 was approximatelv 70% by weight of the charge. although this figure may be materially increased since the still charge was not reduced to a minimum.

During a test,run, the entire distillate, including the lightest and heaviest fractions, obtained from cracking about 850 lbs. `of rosin was collected, and representative samples of the distillate taken at diderent times. `Two of these 'samples were fractionally distilled in a common laboratory Hemple column, the temperature of the vapors being noted as each 5% fraction was collected, and the speciiic gravity of each fraction determined. These data appear in the two curves indicated in Figure 2, the boiling point of the end of the 5% fractions being plotted against their specific gravities. The sample represented by curve 22 was collected comparatively early in the run, that represented by curve 23 being collected at a late'r time.

The small open circles 24 appearing on or near their respective curves indicate the boiling points and gravities of the 5% fractions, f

\. and silice 95% of each of the two samples were distilled and collected, 19 of these 5% fractions are represented on each curve. Although curves 22 and 23 vary somewhat, due probably to changes in temperature conditions during the run` or due to changes in the chargewithin the cracking still during its continued reduction, it isevident that thel curves indicate compounds or fractions having similar properties as regards boiling included in the product boiling range have specific" gravities ranging from around 0.75 up to 0.95, the high densities of the product constituents of the distillate, particularly among the higher boiling fractions, indicating the absence .of substantial quantitiesof aliphatic and naphthenic compounds, which are characterized by comparatively lower kspecific gravity. Moreover, as reviously mentioned, the cracked rosin disti lates, like known aromatic compounds, are soluble in cold 96% sulphuric acid the aliphatic and naphthenic compounds being practically insoluble in this acid.

In order to indicate what compounds might be present in these cracked products, a number of known compounds having specitic gravities and boiling point relationships near the points on these curves* are also shown in Fig. 2 by the relatively large circles. Isoprene appears in the lower left hand corner and considerably out of proximity to the rosin curves, thus indicating that but little isoprene can be present in the distillate. It will also be noted that benzene (benzol) falls a considerable distance below the curves, benzene therefore not being present in the distillate in substantial amounts. Toluene, xylene and their substituted products ysuch as ethyl benzene, normal and isopropyl benzene, santone, styrol, cymene, etc., fall on the curves. It thus appears that substan tially the greater port-ion; of the'cracked products boiling below 450 F. is composed almost entirely of aromatic and varomatic substituted compounds, with the possible exception of a small amount of such substances as.

range of the fuel within these temperature limits in accordance with given specifications. yFor instance, there is indicated -in Fig. 2 the maximum boiling point of a particular grade of U. S. motor gasolinehaving a'n end point around 437 F.

In another run, the still 10 was charged with oil of turpentine and the latter distilled accordi-ng tothe preceding method described for the treatment ofrosin. A representative sample of -the cracked distillate was distilled in a Hempel fractionating column andthe boiling point and specific gravities taken of 5% fractions as in the case of the ,volatility of the lighter fractions may rosin distillate, the results of the tests on the turpentine fractions being indicated by curve 26 in Fig. 2. It will be noted that the thrpentine distillate curve lies'in the same re- -gion and is substantially coincidental with the lower portions of the 'rosin distillate curve 22, the lighter fractions of this particular sample of the turpentine distillate being somewhat more volatile 4than those of the rosin products. The curve 26 indicates therefore that the cracked distillate derived from the oil of turpentine has properties characteristic of the aromatic and quite similar to the distillate obtained from rosin. Of the sample tested, the lighter c-onstituents of the turpentine product have the greater velocity, although it may be stated that the volatility of the rosin distillate may be increased as desired by causing more complete cracking of the rosin vapors by regulatincr the temperature conditions in the superlieater, the curves of course being merely typical of the product and not intended to define its boiling range. Due to the particular nature of the samples and as represented by the curves in Fig. 2, the boiling temperatures of the lightest fractions are somewhat above the hereinabove specified initial boiling point which.

it may be desired that the product have, in accordance with the initial points of certain commercial grades of gasoline. However, as

stated, by-varying the method of production,

for instance the conditions of cracking, the

regulated to give substantially any desired initial boiling temperature to the product. It may be preferred to carry out the method of production in a manner such that the volatility of the lightest fractions in the distillate will correspond to the desired initial boiling points of the fuel product, and the distillate then fractionated in accordance with the end point of the product. Again, it may be desirable to carry out the cracking reaction to such an extent that the heavierfractions of the distillate, that is those having boiling points above 450 F., may be broken'down into fractions having boiling temperatures within the boiling range of the product.

I claim 1. A non-detonating motor fuel composed substantially within 100 to 450 F., and a specific gravity between 0.75 and 0.95.

3. As a product, a liquid material comprising a mixture of compounds of aromatic nature obtained by vaporizing rosin at substantially atmospheric pressure, and then in a subsequent operation cracking the vapors, the compounds of the mixture having specific gravities between 0.7 5 to 0.95, and a boiling range within 100 F; to 450 F.

4. As a product, a motor fuel comprising substantially a mixture ofcompounds of aromatic nature obtained by vaporizing rosinat substantially atmospheric pressure, and-then in a subsequent operation cracking the vapors, said mixture having a boilin range within 100 F. to 450 F., and a speci c gravity between 0.7 5- and 0.95.

5. As a product, a motor fuel derived from rosin by heating and vaporizing said rosin and at substantially atmospheric pressure, subjecting the vapors to cracking at a temperature between 600 F. and 1200 F., and condensing the cracked vapors.

6. As a product,.a motor fuel comprising a mixture of compounds of substantially'aromatic nature obtained'by vaporizing rosin at substantially atmospheric pressure, and then in a subsequent operation crackingthe vapors, said mixture having a boiling range substantially within 100 F. to 450 F.

7. As a product, a motor fuel obtained by vaporizing rosin at substantially atmospheric be` pressure, and then in a subsequent operation cracking the vapors at a temperature between 600 F. and 1200 F., said fuel having a boling range substantially within 100 F. to

day of July 1929. .y

DANIEL W. HOGE.-

of a mixture of gasoline and a liquid m'ate-l l rial comprising substantially a `mixture of compounds of aromatic nature obtained by vaporizing rosin and'cracking-the vapors atv a temperature between 600 F. and 1200 F., i

said liquid material having a boilingrange within 100 F.,to 450 F.

2. A non-detonatingmotor fuel composed of a mixture of gasoline and a liquid material comprising substantially a series of compounds of aromatic nature obtained 'by vaporizing rosin and'cracking the 'vapors at a temperature" between 600 F., and 1200 F.,

said liquid material ,having a boiling range 

